Synchronization of ultra-wideband communications using a transmitted-reference preamble

In a radio frequency (RF) burst communications system comprising a transmitter and a receiver, apparatus for initial synchronization comprising:

• a preamble generator at the transmitter for generating at a transmitter a transmitted-reference preamble, the transmitter transmitting a transmitted-reference, delay-hopped (TR/DH) burst to the receiver;
• a detector at the receiver for detecting the TR/DH burst to generate a time mark;
• a time delay means at the transmitter for measuring a fixed period of time, the duration of which is known to the receiver, following the transmission of the TR/DH burst, the transmitter at the expiration of the fixed period of time transmitting an RF burst transmission;
• and
• a correlation receiver in the receiver and responsive to the time mark for beginning reception of the RF burst transmission from the transmitter and outputting demodulated bits.